Chore: Updates CHANGELOG.md for 7.0.3 (#25331)

* Update CHANGELOG.md

* updated according to feedback.

* Update CHANGELOG.md

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

CHANGELOG.md

+# 7.0.3 (2020-06-03)
+
+### Features / Enhancements
+* **Stats**: include all fields. [#24829](https://github.com/grafana/grafana/pull/24829), [@ryantxu](https://github.com/ryantxu)
+* **Variables**: change VariableEditorList row action Icon to IconButton. [#25217](https://github.com/grafana/grafana/pull/25217), [@hshoff](https://github.com/hshoff)
+
+### Bug Fixes
+* **Cloudwatch**: Fix dimensions of DDoSProtection. [#25317](https://github.com/grafana/grafana/pull/25317), [@papagian](https://github.com/papagian)
+* **Configuration**: Fix env var override of sections containing hyphen. [#25178](https://github.com/grafana/grafana/pull/25178), [@marefr](https://github.com/marefr)
+* **Dashboard**: Get panels in collapsed rows. [#25079](https://github.com/grafana/grafana/pull/25079), [@peterholmberg](https://github.com/peterholmberg)
+* **Do not show alerts tab when alerting is disabled**. [#25285](https://github.com/grafana/grafana/pull/25285), [@dprokop](https://github.com/dprokop)
+* **Jaeger**: fixes cascader option label duration value. [#25129](https://github.com/grafana/grafana/pull/25129), [@Estrax](https://github.com/Estrax)
+* **Transformations**: Fixed Transform tab crash & no update after adding first transform. [#25152](https://github.com/grafana/grafana/pull/25152), [@torkelo](https://github.com/torkelo)
+
 # 7.0.2 (2020-06-03)
 
 - **Security**: Urgent security patch release. Please read more in our [blog](https://grafana.com/blog/2020/06/03/grafana-6.7.4-and-7.0.2-released-with-important-security-fix/)